gpu: ion: Ensure ioctl return correct error codes

Under certain error conditions the following ION ioctl's would return
success even when the operation failed:

-ION_IOC_CLEAN_CACHES
-ION_IOC_INV_CACHES
-ION_IOC_CLEAN_INV_CACHES

Add return of correct error codes when an error occurs.

Change-Id: Ie8824bfecbb423c23d32c6a3d7058f06d8322906
Signed-off-by: Olav Haugan <ohaugan@codeaurora.org>
diff --git a/drivers/gpu/ion/ion.c b/drivers/gpu/ion/ion.c
index bd7729b..ff46cb0 100644
--- a/drivers/gpu/ion/ion.c
+++ b/drivers/gpu/ion/ion.c
@@ -1561,6 +1561,8 @@
 		if (!data.handle)
 			ion_free(client, handle);
 
+		if (ret < 0)
+			return ret;
 		break;
 
 	}